A commercial or residential hot and cold water treatment system that provides treated hot and cold water. The water treatment system may condition or purify the water. The water treatment system may be in a fixed location or be portable.
Rising population and increased urbanization have increased the demand for treated water, particularly for conditioned and healthy potable water. Increasingly, however, the drivers of growth for potable water have also served to decrease the supply. While great strides have been made in treating municipal and industrial waste water before its introduction to streams, spills, breakdown of sewage treatment equipment, the existence of mixed storm/sewage systems, livestock pond overflows, groundwater contamination, and non-point sources of contamination have all served to degrade the existing supply of fresh water.
Coupled with these problems is the fact that conventional municipal and industrial water treatment systems can break down and allow water contaminated with elevated numbers or levels of live organisms to enter the distribution system. Further, even under normal operating conditions, live organisms have been known to evade current treatment systems and be distributed in water supply systems for cities and industries. In 1993, for example, an incident occurred in Milwaukee that resulted in Cryptosporidium entering the municipal drinking water. The contaminated water was subsequently distributed to homes and businesses and imbibed by many individuals. The Milwaukee incident caused an estimated 400,000 people to become ill, about 4,000 were hospitalized, and about 50 died. A recent example (summer 2000) occurred in Ontario, Canada when pathogenic E. coli bacteria entered the municipal distribution system in a town of about 5000 people. The contaminated water was subsequently distributed to homes and businesses and imbibed by many individuals. About 2000 individuals became ill and 11 died. In addition, various weather conditions, distribution system accidents, and equipment malfunctions require more frequent warnings to boil water for personal use on a regular basis throughout the United States. Water supply problems and contamination in less developed countries are far worse than in the United States or Canada. Further, the invention may be useful in alleviation of illnesses and deaths caused by intentional contamination of water systems and water supplies with pathogenic organisms by terrorist groups.
Additionally, present designs and methods of treatment in municipal and industrial potable water treatment plants do not treat or remove all Cryptosporidium or Giardia. According to the US EPA standards for water supplies-the Surface Water Treatment Rule requires systems using surface water, or ground water under the influence of surface water to (1) disinfect their water, and (2) filter their water or meet criteria for avoiding filtration so that the following contaminants are controlled at the following levels compared to the incoming water: 99% of the Cryptosporidia; 99.9% of Giardia lamblia; 99.99% of the viruses; Legionella has no limits but the EPA believes that if Giardia and viruses are controlled, Legionella will also be controlled; the heterotrophic plate count test should show no more than 500 bacterial colonies per milliliter of water. The heterotrophic plate count test will reveal any of several thousand bacteria present in the water including E. coli, and Staphylococcus species. There are also water turbidity tests that are required to show adequate performance of the water treatment plant. Properly operated water systems such as municipal water systems are considered to typically have about 100 heterotrophic microorganisms per milliliter of water. Thus, municipal drinking water still has a number of a variety of organisms when delivered to the consumer.
Municipal drinking water is treated to contain levels of organisms generally acceptable for persons in good health. There remains a low but quantifiable risk of infection from water borne diseases to the general population; however, those with impaired or immature immune systems are at a much higher risk. In this high risk group are typically the elderly, cancer patients, patients being treated with immunosuppressants (e.g. organ-transplant recipients), aids patients or those that are HIV positive, infants and children. Presently there is no treatment for Cryptosporidium infection; however, Giardia infections can be treated by antibiotics. Infections by other pathogenic organisms, even if treatable, often leave residual effects. For those at high risk even properly treated municipal water may still pose an unacceptable risk because of the residual organisms remaining in the water supplied to the homes, medical treatment centers, long term care facilities, or hospitals where people reside or visit for a short time.
One embodiment of the present invention reduces the risk of infection associated with water containing live organisms that subsequently enter the potable water supply of a home or business. The present invention further overcomes these problems in a way that reduces costs associated with providing thermally conditioned or purified water to a home or business.
The present invention also solves a worldwide problem caused by oceangoing shipping. When the ship enters port and is loaded, its ballast water and/or bilge water is typically pumped out. For oceangoing ships, this means that water is pumped into the ship in one part of the world and pumped out again in another. It has been estimated that for the United States alone about 80 million tons of ballast water are discharged into our ports every year. The water typically contains microorganisms, small multicellular animals and plants, small juvenile forms of various animals and plants, reproductive forms of animals, fungi, or plants such as eggs, spores, and seeds.
One proposed method of overcoming this problem is the exchange of ballast water in mid-ocean so as to replace all of the original ballast water with seawater. This solution, however, is usually impractical due to safety and stability concerns during this maneuver. Continuous ocean exchange likewise is not practical. The latter procedure would require redesign of ballast tanks and would still leave a portion of the original ballast water in the tanks.
The spread of microorganisms and multicellular organisms, by commercial and military ships, from their usual habitat to sites around the world has become a major problem today. Diseases not usually encountered in other areas can be spread widely by these ships. Likewise, animals and plants native to a particular habitat can be carried by the ships to another ecosystem. Typically, the introduction of non-native plants and animals will cause upsets in the new ecosystem and may cause local species to become rare or extinct. Additionally, there may be problems with use of the water for drinking or industrial purposes.
A good example of the problem is the introduction of zebra mussels into the Great Lakes in North America. It is believed that zebra mussels were brought into the lakes by ocean going vessels in 1988 that emptied their ballast water into one or more of the Great Lakes. Zebra mussels have multiplied because there was no natural predator, consequently they have grown uncontrolled and spread rapidly altering and damaging the Great Lakes and other ecosystems. By the year 2000, zebra mussels had spread to all states and Canadian provinces bordering the Great Lakes, the St. Lawrence River, the Mississippi River and the Ohio River, including some of their tributaries. The zebra mussels threaten native mollusks and fish. They have already caused great damage to industrial and municipal water delivery systems. Another example, in the reverse, is the introduction of the American comb jelly into the Black and Azov seas that has seriously affected the anchovy and sprat fisheries. A further example includes the possible spread of human diseases carried by water such as cholera and organisms associated with ship-generated waste water.
The above illustrates the problem for only a few species. Many more species can be and are being carried around the world causing local or widespread invasions of nonindiginous species. Therefore, apparatus and methods are needed to prevent the spread of these organisms. The present invention solves this problem in an environmentally safe way without the use of chemicals.
Broadly the invention encompasses a water treatment system for providing a thermal dose to water so as to thermally condition the water to inactivate a predetermined level of selected organisms in the water. One embodiment of the invention typically provides an apparatus for providing conditioned or purified water typically including a heat exchanger for exchanging heat between purified water and makeup water, having a makeup water inlet and a preheated makeup water outlet; at least one heat exchange surface between the purified water and makeup water, a treated water inlet, and at least one or more treated water outlets; and a water heater tank with a tank inlet and a tank outlet, wherein the tank inlet is connected to the heat exchanger makeup water outlet and the tank outlet is connected to the heat exchanger treated water inlet. The one or more treated water outlets are typically located upstream or downstream from each other respectively and provide treated water at different temperatures. Typically a sensing and/or controlling device is included for determining time/temperature relationships at one or more locations of the apparatus to determine if water has been treated to a predetermined amount. The monitoring device may emit signals perceptible to the user as to water conditions or relationships for time, temperature, and so on.
Additional embodiments typically include bypass apparatus for bypassing the heat exchanger during distribution system purification. The apparatus may include a valve connected to the inlet of the heat exchanger, the valve operable to stop makeup water flow to the heat exchanger and redirecting the flow of makeup water; and water lines connected to one outlet of the valve for receiving redirected makeup water from the valve and redirecting the makeup water to the water heater.
A further embodiment of the invention typically includes flow-impeding elements such as diffusers, baffles, and the like. Diffusers typically include brush, cone and screen diffusers that slow the velocity of water entering the water heater or water tank. Baffles typically include fixed and floating baffles such as those known in the art, floating baffles having a plurality of floats of selected specific gravities. One embodiment advantageously uses a heated baffle system to separate and heat hotter and cooler water layers.
An additional embodiment of the invention typically provides a method for purifying or conditioning water by the steps of flowing makeup water into an inlet of a heat exchanger having a makeup water inlet and an outlet for preheated makeup water, and an inlet and one or more treated water outlets in a purified water section of the heat exchanger and preheating the makeup water; flowing the preheated makeup water to a water heater tank; heating the preheated makeup water to a predetermined elevated temperature; holding the heated water above a selected temperature in a portion of the tank so as not to mix with the preheated makeup water for a time sufficient to purify the heated water; flowing the purified water into the inlet of the purified water section of the heat exchanger and cooling the water as it flows through the heat exchanger; withdrawing water through one or more treated water outlets of the purified water section of the heat exchanger.
A still further embodiment typically includes a method for purifying a water distribution system including the steps of providing a water purification system having a bypass system as described herein and shutting off the flow of makeup water to the heat exchanger; bypassing the heat exchanger and flowing makeup water into the inlet of the water heater; and withdrawing hot purified water from the treated water outlets of the heat exchanger, and flowing the water to selected fixtures to purify water distribution lines and fixtures attached to the treated water outlets, until all have been turned on for a sufficient time to purify the plumbing water lines and fixtures leading from the outlets. Typically, the fixtures are turned on for a selected period of time, the water flow is stopped after the temperature of water flowing from a fixture does not change for a second selected period of time, and the fixture and lines allowed to purify at elevated temperature for a third selected period of time sufficient to provide a thermal dose for inactivating at least a predetermined level of selected organisms in water distribution lines of the fixture.
A further embodiment of the invention includes a water treater typically having a heat exchanger for exchanging heat between treated water and makeup water, and having a treated water inlet and a preheated makeup water outlet; and a hot treated water inlet and at least one outlet for withdrawing treated water at a reduced temperature; a water heater with an inlet and an outlet, wherein the water heater inlet is connected to the heat exchanger preheated makeup water outlet and the water heater outlet is connected to the heat exchanger hot treated water inlet; at least one mixing valve with an outlet and at least two inlets having a first inlet connected to one treated water outlet of the heat exchanger, for obtaining treated water at a reduced temperature there from, and a second inlet connected to the water heater outlet for obtaining hot treated water, wherein the mixing valve provides treated water at the mixing valve outlet at an intermediate temperature between the hot treated water and the reduced temperature treated water.
An additional embodiment of the invention provides for a method for providing stratification control in a hot water heater tank, typically by providing a hot water heater having a plurality of mix-impeding elements, the mix-impeding elements having one or more specific gravities corresponding to one or more desired water temperatures, and the mix-impeding elements movable within the hot water heater to adjust to the one or more desired temperatures, impeding the mixing of water above the plurality of mix-impeding elements and water below the mix-impeding elements as the level of the one or more desired temperatures in the hot water tank varies.
A still further embodiment of the invention includes a method for increasing the effective first-hour rating (output capacity, DOE, 1998 see below) of a hot water tank, typically by providing a hot water tank having a first-hour rating (first output capacity) for heating water, and having a heated water outlet for heated water of at least one desired temperature, and a tank inlet; adding a heat exchanger and flowing makeup water into the heat exchanger thereby pre-heating the makeup water and flowing the pre-heated makeup water to the tank inlet; introducing the pre-heated makeup water at an elevated temperature to the hot water tank; using the introduced preheated makeup water to increase the effective first-hour rating (output capacity) of the hot water tank, thereby enabling the water tank to effectively deliver a first-hour rating (second output capacity) of hot water which is greater than the first-hour rating (first output capacity) without the heat exchanger. Typically, the effective capacity may be increased by apparatus for providing stratification control in the hot water tank, including at least one mix-impeding element impeding the mixing of water above the plurality of mix-impeding elements and water below the plurality of mix-impeding elements as the level of one or more desired temperatures in the hot water tank varies; and thereby maintaining the volume of heated water above the plurality of mix-impeding elements at a desired temperature for delivery at the heated water outlet. Typically, the effective capacity may be increased by providing stratification control in the hot water tank, comprising a plurality of mix-impeding elements at one or more specific gravities impeding the mixing of water above the plurality of mix-impeding elements and water below the plurality of mix-impeding elements as the level of one or more desired temperatures in the hot water tank varies; maintaining the volume of heated water above the plurality of mix-impeding elements at the one or more desired temperatures for delivery at the tank outlet; and using the plurality of mix-impeding elements for heating water to more effectively increase the temperature of makeup water to the desired temperature of the heated water, thereby increasing the effective output capacity of the hot water tank.
A yet further embodiment of the invention includes a thermal ballast-water treatment system for a ship typically including a heat treatment system as disclosed herein for heat treating incoming ballast water, outgoing ballast water, and/or stored ballast water; a ballast water tank connected to the heat treatment system for storing treated water or water to be treated; and a pump connected to the heat treatment system and/or ballast water tank. A typical variation of this embodiment includes a method having the steps for thermally treating ship ballast water while pumping water from a ship""s surroundings or from a ship""s interior to a heat treatment system; treating the water with heat using apparatus as disclosed herein to provide a thermal dose sufficient to inactivate a selected percent of selected organisms present in the water; and pumping the treated water to a ballast tank on the ship. A further typical variation of this embodiment includes a method having the steps for thermally treating ship ballast water including pumping water from a ship""s surroundings or from a ship""s interior to a tank on a ship; holding the water in the tank for several hours or more; pumping the held water to a heat treatment system as disclosed herein and treating the water with heat to provide a thermal dose sufficient to inactivate a selected percent of selected organisms present in the water; and discharging the treated water to the environment. Another typical variation of this embodiment includes a method having the steps for thermally treating ship ballast water including pumping water from a ship""s surroundings or from a ship""s interior to a heat treatment system; treating the water with heat to provide a thermal dose sufficient to inactivate a selected percent of selected organisms present in the water; pumping the treated water to a tank on the ship and holding the water in the tank; pumping the held water to the heat treatment system; treating the water in the heat treatment system for a second time with heat to provide a thermal dose sufficient to inactivate a selected percent of selected organisms present in the held water; and pumping the second heat treated water outside the ship.
Another embodiment of the invention includes an apparatus for providing treated water including a heat exchanger typically having a first section and a second section located upstream from the first section for exchanging heat, wherein the first section exchanges heat between water from an auxiliary heater and makeup water, and the second section exchanges heat between water from an auxiliary heater to water from a water tank, the heat exchanger first section having a makeup water inlet and a preheated makeup water outlet; at least one heat exchange surface in the first section between the water from the auxiliary heater and makeup water, the heat exchanger second section having at least one surface between the water from the auxiliary heater and the water from the water tank, the second heat exchanger section having an inlet for water from the auxiliary heater water and an outlet for water to the auxiliary water heater, an inlet for water from the water tank, and the first section has at least one or more treated water outlets; a water heater tank with a tank inlet and a tank outlet, wherein the tank inlet is connected to receive water from the first section heat exchanger makeup water outlet and the tank outlet is connected to deliver water to a second section inlet for water from the water tank; and an auxiliary heater having an inlet connected to an outlet from the second section of the heat exchanger for receiving water from the water tank that has been preheated in the second heat exchanger section, and the auxiliary heater having an outlet connected to the inlet on the second section heat exchanger for water from the auxiliary heater. In some typical applications a delay line or water tank is connected between the outlet of the auxiliary heater and the inlet on the second section heat exchanger receiving water from the auxiliary heater. The delay line or water tank may be included to provide additional thermal treatment time for water that exits the auxiliary heater.
An additional embodiment of the invention includes a heat exchanger for a hot water treating system typically including a treated water to makeup water heat exchanger for exchanging heat between treated water and makeup water, and having a makeup water inlet and a preheated makeup water outlet; and a hot treated water inlet and at least two treated outlets for withdrawing treated water at reduced temperatures; and wherein the treated water outlets provide treated water at different temperatures. The heat exchanger typically has its preheated makeup water outlet connected to a tank-type hot water heater.
A yet additional embodiment includes a purification control system for a plumbing system typically including a heat exchanger having an inlet and an outlet for makeup water, and an inlet for hot water and at least one outlet water at reduced temperature; a three-way valve (or other means such as multiple valves in place of the three way valves) for controlling water flow from at least one outlet at reduced temperature having an inlet for water from the at least one outlet at reduced temperature from heat exchanger, a valve outlet; and a second valve inlet; water lines for flowing hot water from a source of hot purified water to the second valve inlet of the three-way valve. Typically, the purification control system has at least two outlets for supplying water at reduced temperatures from the heat exchanger.